Shifter kart - axle

[Lance15]

It's not how big/powerful you are
...it's all in "how" you "work it"

My !ARRIBA! kart is only ~2.5HP
...& does wheelies quite easily

Hhahhaha love it, best thing I have seen in awhile

 

[madprofessor]

(I want to put a slightly bigger counter sprocket in so the rear sprocket can be smaller. I want to try to gear it for more torque then top speed.

You're sounding like me now Lance, nothing you want to be. I now get everything transposed/ backwards/opposite the first time I think about it. Bigger front sprocket is for more top speed, less torque. Same as smaller rear sprocket is for more top speed, less torque. Bigger front/smaller rear means smaller/shorter gear ratio, and vice versa.
If a 60-tooth rear and a 10-tooth front is a 6:1 ratio. then a 45-tooth rear and a 15-tooth front is only a 3:1 ratio. The higher the ratio (I'm currently on a 9:1 ratio) the more torque power you get in a tradeoff for less top speed, if you want strong acceleration, but don't really want to go 60mph.
If you really do want to go 60mph., you go for a smaller ratio that will make acceleration weaker, but will build up to more top speed.
This subject alone is the very best argument for using a 5.25" bolt circle sprocket hub and split sprockets on the rear. If you don't like the gear ratio's performance you're getting, the split sprocket can be changed out in 5 minutes flat. The only time-consuming part is changing the length of the chain to fit the new ratio. That's why you should always start with the largest rear sprocket (largest gear ratio) you think you'd ever possibly want for strong acceleration, and then maybe reduce it down from there at about $15 each for new split sprockets. That way you only have to remove links from the chain as you go, instead of having to add links (multiple master links) as you go.

 

[anderkart]

1 - CR80 is a 1998 (Putting a new top end on it)

2 - 15 teeth currently (I want to put a slightly bigger counter sprocket in so the rear sprocket can be smaller. I want to try to gear it for more torque then top speed. In my head since the kart has smaller tires then a dirt bike taking one chain link out is way more significant then what it would be on a dirt bike? Please correct me if I'm wrong.)

3 - Yes 11" tall slicks is what I want to run on it.

4 - 55 - 60 MPH range. (In my area there would be few chances of really getting it to top speed so I would prefer to go with more torque but still keeping a good balance between top speed and torque.)

You could keep your 15-counter sprocket and install a 26-tooth axle sprocket for that top speed range.

Here's a couple links to the #428 pitch sprockets that are typically used by guys that race CR-80 Shifterkarts:
Go Kart Sprocket Honda CR 80 - 85 (sharkshifter.com)
Go Kart 40mm 428 Sprocket (sharkshifter.com)

 

[Denny]

Listen to Anderkart he is very knowledgeable and will not give you bad advice.

 

[madprofessor]

I'm listening to anderkart also, trying to learn something. The link for the CR80 shows a transmission with 6 speeds in it apparently built in as part of the engine, ranging from a countershaft gear at 35-tooth for low gear, to a sixth gear countershaft gear at 23-tooth. Really confused about shifter karts now, more than before. That's a lot of gear shifting (6 speed) for only a 34.29% change in gear ratio of the output sprocket (countershaft gear).
.............anderkart, how do those things shift? I had a Honda XR75 little dirtbike almost 5 decades ago that had a 3? or 4? speed tranny with an "automatic clutch" you shifted just by letting off the throttle and clicking the foot lever. How do these CR80 shifterkart things shift?
............Lance, with my new understanding that these little engines with trannys would use small axle sprockets, forget the 5.25" bolt circle hub I suggested earlier, the minimum tooth sprocket would still be too large. Here's a link to something different, a mini-hub that has both a 3.228" and a 2.875" bolt circle..................Steel Multi-Patterned Sprocket / Brake Hub (1" Bore) | AZ2561 | Azusa 2561 | BMI Karts And Parts................
and on this page of lots of hubs you'll see a couple of Righetti Ridolfi hubs (famous Italian) that anderkart might recommend to you..............
Search Results > sprocket hubs (bmikarts.com)

 

[anderkart]

Lance15:
Most all Shifter racekarts use 40mm or 50mm diameter axles, but that would be a much more expensive option than using 1" or 1-1/4" diameter components. There's lots of #428 pitch shifterkart sprockets available for those metric axle diameters, but I haven't had much luck in locating any available for 1" or 1-1/4" axles.

Azusa sells these #428 sprockets in suitable tooth counts, but i haven't any luck in finding 1" or 1-1/4" bore hubs that fit the mounting bolt-circle pattern of these sprockets: Axle Sprockets » Product categories » Azusaparts
You could call or email Azusa and ask if they sell 1" or 1-1/4" bore sprocket hubs that fit any of the 3 different mounting bolt patterns of these sprockets.

Another option would be to buy a #520 pitch counter sprocket to fit the CR-80 from one of the shops that manufacture custom counter sprockets. Like this shop:
AMS Racing - Chain & Sprockets

Then you could install an 1-1/4" diameter axle and use these QRC hubs and shifterkart sprockets:
4-Bolt Hub – QRC Karts
4 Bolt Sprocket 520 – QRC Karts


madprofessor:
Shifter racekarts typically either use a paddle shifter or shift lever like the video in the link I've posted below shows. Their clutch is typically operated by the left side paddle. They only use their manual clutch for starting and stopping, they don't need to use the clutch for shifting. Badger Raceway CR80 Shifter Kart - YouTube

 

[Lance15]

Lance15:
Most all Shifter racekarts use 40mm or 50mm diameter axles, but that would be a much more expensive option than using 1" or 1-1/4" diameter components. There's lots of #428 pitch shifterkart sprockets available for those metric axle diameters, but I haven't had much luck in locating any available for 1" or 1-1/4" axles.

Azusa sells these #428 sprockets in suitable tooth counts, but i haven't any luck in finding 1" or 1-1/4" bore hubs that fit the mounting bolt-circle pattern of these sprockets: Axle Sprockets » Product categories » Azusaparts
You could call or email Azusa and ask if they sell 1" or 1-1/4" bore sprocket hubs that fit any of the 3 different mounting bolt patterns of these sprockets.

Another option would be to buy a #520 pitch counter sprocket to fit the CR-80 from one of the shops that manufacture custom counter sprockets. Like this shop:
AMS Racing - Chain & Sprockets

Then you could install an 1-1/4" diameter axle and use these QRC hubs and shifterkart sprockets:
4-Bolt Hub – QRC Karts
4 Bolt Sprocket 520 – QRC Karts


madprofessor:
Shifter racekarts typically either use a paddle shifter or shift lever like the video in the link I've posted below shows. Their clutch is typically operated by the left side paddle. They only use their manual clutch for starting and stopping, they don't need to use the clutch for shifting. Badger Raceway CR80 Shifter Kart - YouTube

AnderKart,

I have had no luck either finding the correct size. I could do it but like you said it would be very pricey. I have found this but it is meant for roller chains. Could something like this possibly work do you think?

TRITAN 40BS20H X 1 Finished Bore B-Hub Sprocket, 20 Teeth, 1/2" Pitch, 1" Finished Bore: Amazon.com: Industrial & Scientific

TRITAN 40BS20H X 1 Finished Bore B-Hub Sprocket, 20 Teeth, 1/2" Pitch, 1" Finished Bore: Amazon.com: Industrial & Scientific

www.amazon.com

 

[anderkart]

AnderKart,

I have had no luck either finding the correct size. I could do it but like you said it would be very pricey. I have found this but it is meant for roller chains. Could something like this possibly work do you think?

TRITAN 40BS20H X 1 Finished Bore B-Hub Sprocket, 20 Teeth, 1/2" Pitch, 1" Finished Bore: Amazon.com: Industrial & Scientific

TRITAN 40BS20H X 1 Finished Bore B-Hub Sprocket, 20 Teeth, 1/2" Pitch, 1" Finished Bore: Amazon.com: Industrial & Scientific

www.amazon.com

Nope #428 pitch chain has a larger roller diameter than #40 pitch, but I have another plan:

If you want to use a 1" diameter axle:
You could order one of these 32-tooth, #428-pitch sprocket blanks: Go Kart Galaxy - Sprocket Blanks
and this "Azusa Steel mini-hub part#2562-A: Go Kart Galaxy - Hubs & Sprockets. That sprocket comes with a 1" center bore, so it would be easy & accurate to simply place the sprocket and hub on your 1" axle side by side, to mark the locations of the holes you'll need to drill in the sprocket...

PS:
I'm now suggesting you buy a 32-tooth axle sprocket, (instead of 26) because that hub has a 4" outer diameter and there wouldn't be enough clearance between the chain & hub with the smaller diameter 26-tooth sprocket. But you could compensate for this gearing difference by simply replacing your engines 15-tooth counter sprocket with a 13-tooth: Go Kart Sprocket Honda CR 80 - 85 (sharkshifter.com) Your old counter sprocket is probably worn and It'd be a good Idea to start out with all new sprockets and a new high quality #428 chain anyway.

 

[anderkart]

And then If you decided to install a 1-1/4" diameter axle, instead of 1" diameter axle: You could simply enlarge the sprocket blanks center hole to 1-1/4" and purchase the Azusa part# 2566-A 1-1/4" Bore Mini-Hub instead.

I prefer 1-1/4" axles over 1" axles, besides being stronger there's more higher quality (racekart-level) related components readily available; like brake rotors & wheel hubs made to fit racekart rims that you might want for your slicks.. Although it'd definitely end up costing you quite a bit more for 1-1/4" axles and all the related racekart-level components, so your choice.

 

[Lance15]

Nope #428 pitch chain has a larger roller diameter than #40 pitch, but I have another plan:

If you want to use a 1" diameter axle:
You could order one of these 32-tooth, #428-pitch sprocket blanks: Go Kart Galaxy - Sprocket Blanks
and this "Azusa Steel mini-hub part#2562-A: Go Kart Galaxy - Hubs & Sprockets. That sprocket comes with a 1" center bore, so it would be easy & accurate to simply place the sprocket and hub on your 1" axle side by side, to mark the locations of the holes you'll need to drill in the sprocket...

PS:
I'm now suggesting you buy a 32-tooth axle sprocket, (instead of 26) because that hub has a 4" outer diameter and there wouldn't be enough clearance between the chain & hub with the smaller diameter 26-tooth sprocket. But you could compensate for this gearing difference by simply replacing your engines 15-tooth counter sprocket with a 13-tooth: Go Kart Sprocket Honda CR 80 - 85 (sharkshifter.com) Your old counter sprocket is probably worn and It'd be a good Idea to start out with all new sprockets and a new high quality #428 chain anyway.

AnderKart,

Awesome this is perfect! I already had a 1" axle so I'm gonna stick with it and see how it goes. Would of never been able to find this stuff without your help. I appreciate your time and effort!! I will update the forum to let you know how it goes.

Thank you!!

 

[anderkart]

Your welcome Lance

 

[madprofessor]

Thanks for the video, anderkart, made me want go fast turn sideways. Couldn't stop looking at the driver's right hand coming off of the steering wheel to make every shift. I thought the best reason for paddle shifts (on a car at least) was to keep both hands on the wheel at dangerous speeds.
Didn't look like a paddle in the first place, more like a column-mounted stick shift. What am I missing in the big picture of things?